Solar string configurations on opensolar.com

[abudabi]

I've been playing around with it and need to understand why this influences power generation as seen below. Is a watt not a watt ? There's about a 150 watt difference in the 2 setups. Incidentally; opensolar's best string configuration spat out the 1st option.

 

[abudabi]

I thought maybe it was due to the AC/DC ratio differences, but redoing it with equal ratios still shows a difference. Am I just being thick and missing something obvious? Is it maybe because of the inverter efficiency "sweetspot"? Or a glitchy site calc?

 

[RonSwanson]

If you are selecting the same panel and location in all 3 examples, then it's definitely a bad calculation on the site.

 

[abudabi]

If you are selecting the same panel and location in all 3 examples, then it's definitely a bad calculation on the site.

Yeah panels and location/orientation has not changed... only strings.

Thanks

 

[Speedster]

Yeah panels and location/orientation has not changed... only strings.

Thanks

What is the difference between the strings?

 

[abudabi]

What is the difference between the strings?

The amount pf panels... it's in the screenshot

 

[Speedster]

The amount pf panels... it's in the screenshot

Ah, I see. I'm guessing either rounding errors, or they've built in different inefficiencies for differing voltages